Monday, March 28, 2016

For regular blog readers, I should point out that this post is not about networks. It is interesting, nonetheless.

I have been known to occasionally buy wine on eBay. Wine cannot be advertised for sale on the English-language eBay sites without a liquor license (e.g. U.S.A., U.K., Australia, Canada, Ireland). However, it can be sold privately on many of the mainland European sites (eg. Austria, Belgium, France, Germany, Italy, Netherlands, Spain), except to minors — the wine can then easily be sent anywhere within the European Union. Indeed, many wine shops use eBay as one of their online portals.

This is generally a useful thing, because older vintage wines are widely available, usually much cheaper than in wine shops, although the buyer must beware. (In eBay terms, for older wines you are formally buying the bottle, not its contents.) I have purchased some very nice wines from 1950-1990 this way, although I have also had a few rather mediocre ones.

I have not yet been ripped off. Indeed, eBay prides itself on dealing with shonky activities by its members, although these activities still exist, and will presumably continue to do so. Recently, I encountered the following example, which I explain here for your education.

A Milan-based seller recently became active selling old vintages of Barolo wine. This in itself is not unusual, but what attracted my attention was that the seller was offering free shipping, apparently worldwide. That is very unusual, because international shipping costs from Italy are often more expensive than the wine itself. How could the seller afford this? Buyer beware! So, I decided to keep a curious eye on several of the wines. When I did so, an unusual bidding pattern appeared.

I have attached at the bottom of this post images of the final bidding results for all seven of the wines that I followed. Many more wines were offered by the seller, but I have not checked their results. You will note that in all seven cases a previously unknown bidder (ie. one who had never bought anything on eBay before) put in a late bid. In six of the seven cases this newbie bidder won the auction.

This is a quite unbelievable coincidence, and I do not for one moment believe it. I occasionally see newbies bidding high prices on wine, but not seven different newbies bidding on all seven of wines that I am watching. If you are prepared to accept this, then I have this bridge in Brooklyn that I would like to sell you ...

Indeed, this looks exactly like shill bidding — defined as "bids on an item with the intent to artificially increase its price or desirability." Normally, the shill bidder does not win the item, but merely forces the other bidders into bidding artificially high, preferably by forcing them to their maximum possible bid. This happened for one of the seven auctions shown below (the fourth one), in which an inexperienced bidder paid €151 for a wine that no-one else thought was worth more than €100. So, the shill bidder managed to extract an extra €50 of profit from the auction. This also happened for the third auction.

The other five auctions require a somewhat different explanation for their profitability.

Unfortunately, eBay has a mechanism that allows shill bidders to ostensibly "win" the item while still achieving their purpose of forcing another buyer to pay more for the item than they needed to. This is called a Second Chance Offer. After the auction, the highest losing bidder is contacted by the seller and told that they have another chance to buy the item, by paying their maximum bid amount. That is, the purpose of the shill bidding is to reveal the maximum bid — in an auction, normally the maximum bid for the highest bidder is not revealed, only the fact that they bid higher than everyone else (while every else's maximum bid is revealed).

Let's take one example from below, the sixth one. The highest bid is the shill bid (from bidder t***t), which was more than €114 — we do not know the actual bid, but one of the other examples (the fourth one) suggests that it was most likely €150. The second highest bid was €112.98 (from genuine bidder 7***8), and the third highest was €79 (from genuine bidder o***2). This means that, without the shill bid, the item would have sold for €79.50 to bidder 7***8. Instead, a Second Chance Offer is sent to 7***8 for sale of the item at €112.98, with a handsome extra profit of €33 to the seller (in collaboration with the shill bidder, who may or may not actually be a separate person).

Note that this approach to shill bidding does also deal with snipe bidders (ie. those who bid during the last few seconds of the auction — there are some examples below). Snipe bidding is sometimes considered to be immune to the actions of shill bidding (eg. How to snipe a winning bid), whereas in eBay this is not so.

Caveat emptor. Be very wary of Second Chance Offers on eBay. If you want to play safe, ignore them.

Tuesday, March 22, 2016

I have previously pointed out that phylogeny reconstructions exits for legendary figures, cartoon animals, Donald Duck, Pokémon, and dragons (see Faux phylogenies). Another popular topic has been the figures of fantastical literature such as elves, dwarves, goblins, gnomes and trolls. Here I present a few of the better-known ones from around the web.

Finally, we have the genealogy to end all fantasy genealogies. The Lord of the Rings Project has a complete interactive genealogy of all of the works of J.R.R. Tolkien. It is way too large to show here, even in miniature, and is actually a series of genealogies that are not connected. However, it is worth noting that, unlike the above genealogies, while most of the genealogies are tree-like many are actually networks because both sexes are included.

More by chance than by actively searching for it, I stumbled upon another hint
regarding an even earlier language phylogeny than the one we thought was the
earliest so far. This phylogeny (or whatever it is) is mentioned in a recent
article by Zeige (2015), which was published in a special
issue of the Zoologischer Anzeiger (A Journal of Comparative Zoology) in
which the topic of morphology across different sciences was discussed. Note
that "morphology" in linguistics refers to the way words are composed from other
words, or words are modified by means of inflection or derivation. So, although
the term originally stems from biology, it has started to live a life of its own in
linguistics.

Since the book is written in both Latin and German, it also contains the same schema in a Latin version:

Schottel's classification in Latin

Schottel has classified the Germanic languages and dialects. That we have a branching scheme here is obvious — that is, a nested set of groups, which could be represented as a dichotomous tree. His schema does
not coincide with our modern phylogenetic classification of the
Germanic languages, but it comes surprisingly close to it.
The key question, however, as David pointed out in an email to me, is whether the
classification was intended to represent the development of the
languages.

Here, we have a general problem in linguistics, namely that
linguists
often did not and still do not distinguish between a classification that
is
intended to represent some observed similarities (which we would call a
"synchronic classification" in linguistics), and a genealogical classification that
is intended to represent the historical dynamics (which we would call
"diachronic classification"). This is also mentioned in Zeige's (2015)
article in the context of Schottel's classification; and in an an earlier blog
post on the Wave
theory of linguistic development,
we saw
how linguists tried to establish an alternative to the family tree but replaced the
historical tree by a static, synchronic schema that was no longer genealogical.
Schottel published his book in 1663, more
than 150 years before Rasmus Rask (1818), Jacob Grimm
(1822), and Franz Bopp (1816) began to
systematize language comparisons, and when reading Schottel's book one can
easily see that he lacks the systematic understanding of language change as a
regular process, which layed the foundation for historical linguistics as a
scientific discipline in the 19th century. For this reason, it is difficult to tell exactly what
Schottel wanted to show with his schema of the Germanic languages and
dialects.

Yet, it is obvious in his book that Schottel had some idea of language diversification as a historical
process, and (in my opinion) also in his
classification schema. He writes, for example, that Germanic languages like
Norwegian, Danish, and Gothic are only remotely "Teutsch" (Germanic), due to
the blurred pronunciations ("unkentlich Machung") and introduction of foreign
words ("Einmengung der frömden Wörter), thus pointing to processes by which the
languages diverged from the Germanic "ideal". Similarily, he mentions that
the old German pronunciation is more easily perceivable in the Lower German and
Lower Saxon languages ("darin die alte Teutsche Ausrede mehr zu spüren").
Moreover, on page 152 in the laudation, Schottel mentions explicitly a split of
the former Germanic language into a High German and a German branch ("Teutsche
und the-ho-uetsche (Hochteutsche) Sprache"), and even mentions the sound change
from [t] to [z]
(compare German zwei vs. English two) that reflects this split.

So, even if the schema reflects the typical uncertainty between static
classification and dynamic genealogy, Schottel's work clearly shows
tendencies
of historical thinking. And for this reason, I would say that the
current score for early phylogenies is 2 for linguistics versus 0 for
biology, at least as far as the 17th century is concerned.
But I am convinced that the last word on this "battle" for priority between biology and
humanities has not yet been spoken!

Tuesday, March 8, 2016

This blog has emphasized that phylogenetic networks are fundamentally different from other types of biological network. For most networks, the nodes and the edges are observed — the nodes represent objects (organisms, proteins, species, etc), and the edges represent known interactions between the objects (so that they are sometimes called interaction networks).

For phylogenetic networks, on the other hand, the leaf nodes are observed while most of the internal nodes are inferred (except perhaps in population studies) and all of the edges are inferred. These networks rarely make it into books with "biological networks" in the title.

That does not make interaction networks uninteresting, of course. Indeed, they can be an excellent way of summarizing complex data. Below, I illustrate three examples from the humanities, just to emphasize how different they are from phylogenetic networks.

The first example is from Martin Grandjean's blog. You can download the full-size network poster from there. What the networks show is the structure of Shakespeare’s tragedies — I have chosen the play Macbeath for illustration. Two characters are connected in each network every time they appear in the same scene. The Network Density is a measures of how complete is the network (ie. all possible edges between its nodes). As you can see, Macbeth himself is at the centre of several poorly connected groups of people in the play.

The second example is from the Moovel Lab web page. You can check out the interactive graphic there. What the network shows is all of the roads that lead to Rome (ie. the shortest road route to Rome from any given point in Europe or Asia Minor). You will note that it is basically tree-like, as expected, but the sea routes form reticulations.

The third example is from Kieran Healy's blog. You can read the full explanation there. It concerns the historical figure Paul Revere, who was involved in the American Revolution. The fable tells us that he rode through the night calling out "The British are coming", but for a number of simple reasons this must be pure poppycock. The following network shows you what was his real role. There were a number of groups of people who banded together to ignite the revolution, and the members of these groups are connected pairwise in the network. The network is very clustered, indicating that these groups had few members in common. If you look closely, you will see that Paul Revere was the only person involved in all of the groups. This makes him a far more important person that history has credited him.

In spite of a number of vocal (and influential) proponents, especially in linguistics and stemmatology, one of the principal criticisms of phylogenetic practice is the use of a tree model. There has simply been too much cross-fertilization in human history for a divergent model of evolution to be viable. A network seems intuitively to be a better model than a tree.

Nevertheless, the extent to which tree models are imposed on representations of anthropological histories varies considerably. Indeed, several people have argued for the use of trees even in the face of reticulate histories.

It seems to me that one interesting example of this variation concerns the history of religions. Below I show several examples of such phylogenetic histories gathered from around the web. These start with the most tree-like ones and proceed to more realistic representations. However, even the most reticulate one is still basically a "tree covered in vines".

The fully scalable version of this final one is available in Wikimedia.